EP3910326A1 - System for detecting and / or determining the volume of bodies or materials made from dielectric and / or conductive material - Google Patents

Abstract

The invention relates to a system for recognizing and / or determining the volume of bodies or substances made of dielectric and / or conductive material (500, 502, 503, 504) within an interior of a measuring cell (400), in particular in the form of a container, with a conductive and / or non-conductive measuring cell wall (401), which has a surface directed into the interior, comprising: - an ultra-broadband microwave unit (201), and - at least one ultra-broadband antenna (202) with at least one disk-shaped carrier substrate (205) with one to one First surface facing the first side and a second surface facing opposite to the first surface, which forms an outside of the antenna, wherein the carrier substrate is arranged and provided, during operation, in particular after fastening the ultra-broadband antenna to the measuring cell, part of the interior space to replace directed surface of the measuring cell wall or spaced in the interior to extend in front of the measuring cell wall, characterized in that the ultra-broadband antenna with radiator elements arranged on or in the carrier substrate is set up as an electrically short antenna with an at least substantially hemispherical radiation characteristic, for covering a volumetric measuring field (700).

Description

The invention relates to a system for recognizing and / or determining the volume of bodies or substances made of dielectric and / or conductive material within an interior of a measuring cell, in particular in the form of a container, with a conductive and / or non-conductive measuring cell wall that has a surface directed into the interior having.

Particularly in the course of the trend towards the intelligent factory as part of the future project Industry 4.0, manufacturing companies have to face considerable tasks. For example, greater flexibility is required, the products must be customizable, and at the same time the products and manufacturing processes are becoming more complex. Individual production also goes hand in hand with lower production quantities from batch size 1, which make more flexible production systems necessary. In order to achieve a consistently high production quality even with small consumption quantities and dynamic processes, all relevant control variables must be permanently available. This also includes the fill quantities and material distributions of liquids, viscous substances and free-flowing bulk goods in an increasing number of small storage and process containers that have to be continuously recorded by sensors.

For example, sensors will also be required in the future that provide information on volumetric product distribution in a contactless manner and / or are suitable for level measurements through material layers.

Nowadays, level measurements are carried out using a wide variety of measurement methods, a basic distinction being made between limit level measurement and continuous measurement. For limit level measurements, several sensors are usually installed at defined height positions in the container wall or vertically from above, so that these mostly only serve to avoid overfilling or idling. Continuous level measurements, on the other hand, provide much more specific information and are advantageous, for example, when several limit levels above the level are to be generated. In the case of continuous level sensors, a distinction is made, as is well known, between sensors that come into contact with the product and those that measure in a non-contact manner. In all types of sensors that come into contact with the product, the measuring electrodes extend over a defined filling level in the container and are always in contact with the product, ie they must meet the environmental conditions in the container. Complicated container geometries, such as corners, slopes, changes in diameter, or built-in components such as filling / heating devices and / or agitators, atmospheric disturbances and chemical and physical properties of the medium, such as viscosity, steam, foam, reactivity, change in density, can impair the measurement or even make it impossible.

Ideally, every measurement should therefore take place from the outside, at least without contact with the product. Contactless measuring sensors work, for example, on the basis of ultrasound, microwaves, radiometry or with radar. With pulse radar, for example, short impulses are sent from above into the container and when these hit the boundary surface of the medium, part of the energy is reflected and can be detected as an echo. The distance to the sensor is then determined from the transit time of the captured signal and the fill level is ultimately calculated using the specified container height. Traditionally, radar systems with a beam that is as narrow as possible are used to capture only reflections from the product surface. In this way, however, strongly bundling antennas are usually used, which, however, only lead to practical sizes at high frequencies and can then only detect a small area of the surface, which can lead to considerable differences between the measured value and the actual filling quantity if there are cones of material. Due to the usually narrow beam lobes or small opening angles of today's radar sensors, pouring cones are usually not detected outside the beam lobe and can consequently lead to a considerable difference between the measured level and the actual fill quantity. These sensors also have a dead zone, especially in the vicinity of the antenna Field area in which the measurement accuracy decreases significantly and the existing container volume can therefore only be used incompletely.

the DE 10 2006 019 688 B4 describes, for example, a planar antenna for a fill level radar for sensor level detection, with a glass or ceramic pane being provided for process separation, on the back of which, ie on the side facing away from the fill level area to be detected by sensors, at least one planar radiator element is applied and spaced therefrom on the side facing away from the fill level area to be detected by sensors, a metal wall is also provided as a ground surface for the radiator element. The planar antenna structure applied by the at least one radiator element is made of a conductive material and can be a single patch radiator or an array made up of several individual patches. This generates an electromagnetic high-frequency transmission signal with a wavelength λ and emits it through the pane to the filling material, which has a thickness of a multiple of λ / 2 in order to minimize the interference. To maximize the bandwidth of the antenna, a gas, e.g. B. air, or a vacuum with a low dielectric constant. Furthermore, according to DE 10 2006 019 688 B4 It is provided that such a planar antenna, which is additionally designed with process separation, is again used in particular within a horn antenna or for installation in a waveguide.

Apart from the thus in the DE 10 2006 019 688 B4 The proposed non-contact measurement, in which at least all electronic components of the sensors are located outside the fill level range to be detected by sensors, would still be much more advantageous, especially for product or object detection in more complex container structures, a wider beam.

One object of the invention is therefore to improve a non-contact measurement within a measuring cell in such a way that even geometrically complex measuring cell volumes are essentially complete and therefore in particular without Dead areas in relation to bodies or substances can be detected with an inexpensive construction.

The solution of the invention is given by a system having the features according to claim 1. Appropriate further training is the subject of the submissions.

According to the invention is thus for the detection and / or volume determination of bodies or substances made of dielectric and / or conductive material within an interior of a measuring cell, in particular in the form of a container, with a conductive and / or non-conductive measuring cell wall, which has a surface directed into the interior , a system arranged as follows.

It comprises an ultra-broadband microwave unit and at least one ultra-broadband antenna with at least one disk-shaped carrier substrate having a first surface facing a first side and a second surface facing opposite to the first surface, which forms an outer side of the antenna. That is to say, the first surface directed towards the first side is expediently located on the side facing away from the filling level area to be detected by sensors. The carrier substrate is also arranged and intended to replace part of the surface of the measuring cell wall directed into the interior during operation, i.e., in particular after fastening the ultra-wideband antenna to the measuring cell, or to extend in the interior at a distance in front of the measuring cell wall. The system according to the invention is further characterized in that the ultra-broadband antenna with radiator elements arranged on or in the carrier substrate is set up as an electrically short antenna with an at least substantially hemispherical radiation characteristic to cover a voluminous measurement field.

It is therefore advantageous that the ultra-broadband signals that can be used through the use of the ultra-broadband microwave unit and antenna, i.e. with a large bandwidth and at the same time low center frequencies, particularly in the single-digit GHz range, can penetrate a wide variety of materials, which on the one hand supports a volumetric measurement and on the other hand the the technical requirements of the electronics required for this are minimized. The measurement signals obtained in this way can then be processed and, in particular, evaluated by subordinate digital algorithms depending on the application. In other words, the signal evaluation shifted away from ultra-broadband electronics to digital algorithms with the system according to the invention allows measurements down to the bottom and in a wide variety of areas including corners of a measuring cell, ie in particular up to the bottom of the container and up to the corners of a measuring cell Container, in particular taking into account transit time and signal shape analyzes, in particular also in the presence of multiple reflections of the measurement field, can be carried out extremely precisely.

Furthermore, since the carrier substrate of the ultra-broadband antenna replaces part of the surface of the measuring cell wall directed into the interior space or extends in the interior space at a distance from the measuring cell wall and the radiator elements arranged thereon or in it have an at least essentially hemispherical radiation characteristic, dead areas can essentially be completely avoided and that The system can therefore also be used for measurements in the vicinity of the antenna.

It has also been shown that particularly useful radiation characteristics can be set up if the system has two planar radiator elements arranged on or in the carrier substrate, which extend essentially parallel to the carrier substrate and are held in a common plane and together form a surface dipole. It is advantageous that the radiator elements can basically be of any shape in order to form a large number of possible antenna structures, such as, for example, circular, elliptical and ring structures or also butterfly structures, fly structures, ie "bow tie" structures and so-called Batwing structures. A coaxial conductor connection, to which the ultra-broadband microwave unit is also connected, is then expediently connected to these radiator elements, specifically for the wired transmission of an ultra-broadband signal between the radiator elements and the ultra-broadband microwave unit.

In a further particularly preferred embodiment, the invention also provides that the system is set up horizontally and / or vertically parallel to the two planar radiator elements with at least two further planar radiator elements, two of these at least two further planar radiator elements extending essentially parallel to the carrier substrate are held by this in each case in a common plane to each other, and together form a surface dipole.

A preferred development provides that a coaxial conductor connection for the wired transmission of an ultra-broadband signal between these radiator elements and the ultra-wideband microwave unit also connected to this coaxial conductor connection is connected to each of these two further emitter elements forming a surface dipole. It is advantageous that the two planar radiator elements and the at least two further planar radiator elements can be connected via the same coaxial conductor connection or also different coaxial conductor connections, so that a large number of individually different bi-static and monostatic antenna structures can be formed with such further surface dipoles, depending on the application .

Each coaxial conductor connection is expediently connected via at least one matching element, in particular for impedance conversion, expediently comprising a balun transformer, to the radiator elements each forming a surface dipole.

Furthermore, it is provided in a supplementary and / or alternative embodiment that the ultra-broadband antenna comprises a shielding arranged at a distance from the carrier substrate towards the first side, ie in particular on the side facing away from the filling level area to be sensed by sensors, when viewed from the carrier substrate. Wave propagation of the ultra-broadband signal in this direction can thus be avoided in a simple manner and the field propagation behind the antenna can be minimized. It is provided in particular that the shield is not connected to the ultra-broadband microwave unit and / or that the shield is formed directly by a metallic measuring cell wall or by a cover of the ultra-broadband antenna.

When using an adapter and a shield, it is further provided according to a preferred development that the adapter is arranged between the shield and the carrier substrate.

In addition and / or as an alternative to the shielding, a surface facing the first side adjacent to the carrier substrate can also be arranged as a protective layer, a non-conductive layer, in particular for covering, and / or an absorber layer, in particular for electromagnetic absorption. With at least one such layer designed for covering and / or absorption, additional reflections on rear-side layers, in particular also grounded layers, can thus be avoided in a simple manner.

In this case, according to an expedient embodiment, the adapter element is embedded in the protective layer.

It has also proven to be particularly expedient if the ultra-broadband microwave unit is set up for a continuously periodic signal as an ultra-broadband signal, an ultra-broadband M-sequence signal having been shown to be particularly expedient, i.e. in particular a pseudo-coded or pseudo-random maximum or maximum signal Noise Sequence Signal.

In addition, the ultra-broadband microwave unit has at least one transmission module for generating the ultra-broadband signal and, in an expedient embodiment, can also include an evaluation module for evaluating a received ultra-broadband signal.

According to a preferred embodiment it is further provided that the system is set up with at least one further ultra-wideband antenna according to prescribed features, this at least one further ultra-wideband antenna being connected to at least one evaluation module for evaluating a received ultra-wideband signal.

As a result, several ultra-broadband antennas, each with at least one carrier substrate, which replaces part of the surface of the measuring cell wall directed into the interior, or extends in the interior and at a distance in front of the measuring cell wall, can be used, in particular for evaluating a received ultra-broadband signal at various Locations within the measuring cell.

A multi-layer circuit board can expediently also be used as the carrier substrate and / or the radiator elements can be embedded in the substrate.

Fig. 1

eine erste Ausführungsform eines erfindungsgemäßen Systems zur Erkennung und/oder Volumenbestimmung von Körpern oder Stoffen in einem beliebig strukturierten Behälter als Beispiel einer möglichen Messzelle,

Fig. 2

eine zweite Ausführungsform eines erfindungsgemäßen Systems zur Erkennung und/oder Volumenbestimmung von Körpern oder Stoffen in einem beliebig strukturierten Behälter als Beispiel einer möglichen Messzelle,

Fig. 3

eine dritte Ausführungsform eines erfindungsgemäßen Systems zur Erkennung und/oder Volumenbestimmung von Körpern oder Stoffen in einem beliebig strukturierten Behälter als Beispiel einer möglichen Messzelle,

Fig. 4

in Draufsicht eine erste Ausführungsform einer Dipolantenne für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 5

in Querschnittsansicht eine zweite Ausführung einer Dipolantenne mit eingebetteten Strahlerelementen für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 6

in Draufsicht eine dritte Ausführung einer Dipolantenne, insbesondere für bistatische Messungen für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 7

in Querschnittsansicht eine vierte Ausführung einer Dipolantenne mit eingebetteten Strahlerelementen für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 8

in Querschnittsansicht eine fünfte Ausführung einer Dipolantenne mit eingebetteten Strahlerelementen und rückseitiger Abschirmung für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 9

in Querschnittsansicht eine sechste Ausführung einer Dipolantenne mit eingebetteten Strahlerelementen für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 10

in Querschnittsansicht eine siebte Ausführung einer Dipolantenne mit eingebetteten Strahlerelementen für den Einsatz innerhalb eines Systems gemäß der Erfindung für den Einsatz innerhalb eines Systems gemäß der Erfindung,

Fig. 11

im Querschnitt ein Messsystem nach dem Stand der Technik mit bündelnden Hochfrequenzantennen bei der Füllstanderfassung in einem Behälter,

Fig. 12

im Querschnitt das Messsystem nach dem Stand der Technik mit bündelnden Hochfrequenzantennen bei der Objekterfassung in einem Behälter, und

Fig. 13

im Querschnitt das Messsystem nach dem Stand der Technik mit bündelnden Hochfrequenzantennen bei der Objekterfassung in einem anderen Behälter.

Further advantages and features of the invention emerge from the following description of some preferred embodiments with reference to the accompanying drawings. The drawings each show a sketch in a greatly simplified, not to scale representation:

Fig. 1

a first embodiment of a system according to the invention for recognizing and / or determining the volume of bodies or substances in any structured container as an example of a possible measuring cell,

Fig. 2

a second embodiment of a system according to the invention for recognizing and / or determining the volume of bodies or substances in any structured container as an example of a possible measuring cell,

Fig. 3

a third embodiment of a system according to the invention for recognizing and / or determining the volume of bodies or substances in any structured container as an example of a possible measuring cell,

Fig. 4

in plan view a first embodiment of a dipole antenna for use within a system according to the invention,

Fig. 5

a cross-sectional view of a second embodiment of a dipole antenna with embedded radiator elements for use within a system according to the invention,

Fig. 6

a top view of a third embodiment of a dipole antenna, in particular for bistatic measurements for use within a system according to the invention,

Fig. 7

a cross-sectional view of a fourth embodiment of a dipole antenna with embedded radiator elements for use within a system according to the invention,

Fig. 8

a cross-sectional view of a fifth embodiment of a dipole antenna with embedded radiator elements and rear shielding for use within a system according to the invention,

Fig. 9

a cross-sectional view of a sixth embodiment of a dipole antenna with embedded radiator elements for use within a system according to the invention,

Fig. 10

a cross-sectional view of a seventh embodiment of a dipole antenna with embedded radiator elements for use within a system according to the invention for use within a system according to the invention,

Fig. 11

a cross-section of a measuring system according to the state of the art with bundling high-frequency antennas for level detection in a container,

Fig. 12

in cross section the measuring system according to the state of the art with bundling high-frequency antennas for the detection of objects in a container, and

Fig. 13

in cross-section the measuring system according to the state of the art with bundling high-frequency antennas when detecting objects in another container.

In the following, for a further description of some preferred embodiments of the invention, reference is made to the figures, whereby, for an improved comparison of the systems according to the invention, first briefly refer to the FIGS Figs. 11 to 13 The systems shown here show which measuring systems according to the state of the art with bundling high-frequency antennas for level and object detection in different containers.

In particular, those in the Figs. 11 to 13 Systems shown in cross-section each have a level radar 100 with antennas (or an antenna) 102 that bundle high-frequency beams be, for example in the DE 10 2006 019 688 B4 described. The bundling antennas 102 are each electrically conductively connected to a rear side, ie on the side facing away from the fill level area to be detected by sensors, to a ground surface or reflector layer 103, a high-frequency connection 104 leading from the bundling antenna 102 to microwave electronics 101. According to the Figs. 11 and 12 each shows a “cuboid” or also “cylindrical” container 300 with a container wall 301, through which a measuring cell is defined. That is to say, the container wall 301 forms the measuring cell wall, so that the surface of the container wall 301 directed into the interior ultimately defines the fill level range to be detected by sensors. Such a filling level area is consequently essentially “hollow cuboid” or also “hollow cylindrical”. As a modification of the Figs. 11 and 12 is at Fig. 13 not a merely “cuboid” or also “cylindrical” container, but a container 400 with an essentially arbitrary structure, in particular arbitrarily complex Structure shown, which consequently also comprises a container wall 401 following this arbitrary structure. A measuring cell defined in this way is defined and thus also the fill level area defined by the surface of the container wall 401 directed into the interior space, which is to be detected by sensors, is consequently not only "hollow cuboid" or also "hollow cylindrical", but can be steps, corners, bevels and the like include.

A measurement field 600 generated in each case by means of the bundling antenna 102 is likewise shown in FIG Figs. 11 to 13 outlined. As can be seen, the generated measuring field 600 is a bundled measuring field and consequently has in particular a correspondingly bundled directional lobe 601 which delimits the area in which a transmission signal 602 can be generated with a certain minimum field strength or a reception signal 603 can be received with a certain minimum signal strength .

Located in the container 300 according to Fig. 11 as filling material 500, for example, a liquid or a bulk material, so that the filling level area and thus the interior of the measuring cell are filled with the liquid or the bulk material essentially homogeneously from the bottom upwards, a level detection with the at Fig. 11 The measurement system shown according to the prior art can essentially be carried out satisfactorily, since in such a case of a homogeneous product distribution a bundled directional lobe 601 generally does not have any negative effects on the measurement result.

Located in the container 300 according to Figs. 12 and 13 However, as filling material, several bodies or substances, such as those marked with 502 and 503, which do not fill the filling level area and thus the interior of the measuring cell upwards homogeneously or are arranged in the interior of the measuring cell distributed from one another, the bundled directional lobe 601 can consequently lead to this that only some of the bodies or substances or only individual bodies or substances within the area of the directional lobe are sensed, ie can be recognized in the Figs. 12 and 13 eg only the body marked with 502. But also a level measurement based on a recognized body or according to Figs. 12 and 13 a volume determination can already lead to different results in these exemplary embodiments. It is like that with Fig. 12 to see, for example, the body 502 on the bottom of the "cuboid" or "cylindrical" container there and the measuring field 600 extends within the directional lobe 601 around the body 502 to the bottom of the container Body 502, in addition to the mere detection of the body, a volume determination of the body can generally also be carried out using appropriate electronics. If, on the other hand, the body is in the near field area of the antenna, such as the body 502 in FIG Fig. 13 , is therefore associated with the Fig. 13 The measurement system shown according to the prior art only detects part of the body 502. Consequently, the body 502 can in principle be recognized on the basis of the body surface 504 of the body 502 detected by sensors, but the volume of the body can generally no longer be determined. In addition, it has a negative complementary effect when the body, such as the body 502, for example Fig. 13 does not lie on the bottom of a merely "cuboid" or "cylindrical" container, but rather, for example, on a shoulder or on other further bodies arranged individually under the body. The body surface 504 of the body 502 detected by sensors can in fact reflect an incorrect fill level in such a case. Of both Figs. 12 and 13 However, bodies 503 located outside of directional lobe 601 cannot be detected at all, in particular since its body surface 504 is no longer detected by sensors by means of measurement field 600 either.

In contrast, the Figs. 1 to 3 in a greatly simplified representation various measuring systems according to the invention. In particular, three different embodiments of a system 200 according to the invention for recognizing and / or determining the volume of bodies or substances in an arbitrarily structured container are sketched as an example of a possible measuring cell 400.

As can be seen below, such a system 200 according to the invention is suitable for recognizing and / or determining the volume of bodies or substances made of dielectric and / or conductive material 500, 502, 503, 504 within an interior of the measuring cell 400, and thus in particular in the form of a container, with a conductive and / or non-conductive measuring cell wall 401, which has a surface directed into the interior. In the present exemplary embodiments, too, the container wall thus forms the measuring cell wall 401, so that the surface of the container wall directed into the interior space ultimately defines the fill level range to be detected by sensors. Such a or similar measuring cell and thus also the filling level area to be detected by sensors inside the measuring cell is consequently not just "hollow cuboid" or "hollow cylinder-shaped", but can include steps, corners, bevels and the like, as well in the Figs. 1 to 3 you can see.

The system according to the invention here has an ultra-broadband microwave unit 201 and at least one ultra-broadband antenna 202. This is connected to the ultra-broadband microwave unit 201 in a practical embodiment. A component of the ultra-wideband antenna 202 is at least one disk-shaped carrier substrate with a first surface directed towards a first side and a second surface directed towards a first surface. This second surface forms an outside of the antenna and the carrier substrate 205 is arranged and provided in such a way during operation, that is to say in particular after the ultra-broadband antenna has been attached to the measuring cell, for example in the Figs. 1 to 3 indicated to replace part of the surface of the measuring cell wall directed into the interior. Alternatively, the carrier substrate can, however, also extend in the interior space at a distance in front of the measuring cell wall. Such as the Figures 4 to 10 As can be seen, emitter elements 206a, 206b, 207a, 207b are arranged on or in the carrier substrate 205 in such a way that they are set up as an electrically short antenna with an at least substantially hemispherical radiation pattern in order to create a voluminous measurement field 700, such as the Figures 1 to 3 to be taken as an example, to cover.

As is well known, it is an electrically short antenna if the electrical conductor of the antenna is much smaller than half the operating wavelength λ: In the present case, i.e. when using an ultra-broadband microwave unit and antenna and the ultra-broadband signals that can be used with it, i.e. for signals especially within one Frequency range between 0.1 to 6 GHz, the wavelengths move approximately in the range between 30dm to 5cm during operation, depending on the desired application, half an operating wavelength therefore preferably moves between 15dm to 2.5cm and the electrical conductor or the conductor structure of the The antenna elements that make up the antenna must be adapted accordingly as far as possible. In particular, it is provided that the electrical conductor or the conductor structure of the radiator elements according to the definition from " Textbook of High Frequency Technology ", first volume, second edition, page 261, chapter 6.2.2, from 1973, ISBN 3-540-05974-1 , to set up an electrically short antenna is less than or equal to λ / 8.

As already explained, ultra-broadband signals with low frequencies are provided in order to be able to penetrate a wide variety of dielectric materials particularly well. In addition, correspondingly small antennas with radiator elements in the centimeter range are required and provided for small measuring cells. When considering the entire usable frequency range, it is by definition electrically short antennas that have little or no directional effect and thus expediently support a volumetric field spread or measurement,

In other words, the radiator elements 206a, 206b, 207a, 207b arranged on or in the carrier substrate 205 are set up to cover a volumetric measurement field 700 over a solid angle of at least 2π.

In this way, in the subject matter of the prior art described above, with a system according to the invention, even in geometrically complex measuring cells and thus geometrically complex fill level areas to be detected by sensors, dead areas can be essentially completely avoided and it can therefore also be used for measurements, in particular radar measurements, for detection and / or volume determination of bodies or substances in the vicinity of the antenna can be used.

In particular, when the carrier substrate extends at a distance in front of the measuring cell wall in the interior during operation, radiation characteristics have also been shown to be particularly preferred with which a voluminous measuring field 700 over a Solid angles of far more than 2π up to 4π can be covered and the radiation pattern thus extends to a fully spherical radiation pattern.

In the measuring system 200 according to the invention, too, a high-frequency connection 203 expediently leads from the ultra-wideband antenna 202 to the ultra-wideband microwave unit 201, for the wired transmission of an ultra-wideband signal to the ultra-wideband microwave unit 201, ie in particular a coaxial connection connected to the radiator elements for the wired transmission of the ultra-wideband signal between the radiating elements and the ultra-wideband microwave unit 201.

There are consequently in a measuring cell 400 with shoulders, corners, slopes and the like, for example in the container according to FIG Fig. 1 or 2 , which has a similar, ie arbitrarily complex structure as the container according to Fig. 13 has, however, as filling material, several bodies or substances, such as those marked with 502 and 503, which do not fill the filling level area and thus the interior of the measuring cell homogeneously from the bottom upwards or are arranged inside the measuring cell distributed from one another, can consequently due to the covering of the volumetric measurement field 700 over a solid angle of at least 2π, based on the body surfaces 504 detected by sensors, both of the body 502 and also of the body 503, also the multiple bodies or substances recognized and / or, in particular depending on the application-specific further configuration of digital algorithms used for signal evaluation, can be determined in their respective volume. As in FIGS. outlined, with the help of the at least substantially hemispherical radiation characteristic of the ultra-broadband antenna according to the invention, dead areas are thus substantially completely avoided and the system 200 can thus also be used for measurements in the vicinity of the antenna.

In order to generate the ultra-broadband signal used for the measurement, the ultra-broadband microwave unit consequently expediently has a transmission module and / or for the transmission module (not shown in greater detail in the figures for reasons of clarity) Evaluation of a received ultra-wideband signal is expediently an evaluation module, which is likewise not shown in detail in the figures for reasons of clarity.

Exemplary transmission signals and also transmission signals reflected on the measuring cell wall within the volumetric measuring field 700 are shown in FIG Figs. 1 and 2 marked with 702 and 704 and exemplary received signals as well as received signals reflected on the measuring cell wall are marked with 703 and 705, respectively.

With the system according to the invention, measurements, in particular radar measurements down to the floor and in a wide variety of areas including corners of a measuring cell, ie in particular up to the container floor and up to the corners of a container, expediently including using reflected signals and taking into account of time-of-flight analyzes and multiple reflections, can be evaluated extremely precisely, in particular using digital algorithms. It should be noted here, however, that the signal evaluation itself, in particular when using appropriate algorithms, is not the subject of the invention and is consequently not discussed further.

However, it should also be pointed out that the ultra-broadband antenna 202 does not necessarily have to be designed as a transmitting and receiving antenna. In the context of the invention, it is also provided in particular that the system is set up with at least one further ultra-broadband antenna, so that a first of the antennas is set up as a transmitting antenna and one or more further antenna (s) are set up as receiving antennas. In this case in particular, this at least one further ultra-broadband antenna is connected to at least one evaluation module for evaluating a received ultra-broadband signal. This evaluation module is preferably the evaluation module already mentioned above in relation to the ultra-broadband microwave unit, with several evaluation modules also being able to be connected to one another for joint signal evaluation. Alternatively, several antennas can also be set up as transmitting antennas and only one or more of the further antenna (s) as receiving antenna. Furthermore, alternatively, several antennas can also be set up as transmitting and receiving antennas or, in a further alternative, several antennas can be set up as transmitting and receiving antennas and one or more antennas can be set up as receiving antennas.

As a result, the system according to the invention can also have several ultra-broadband antennas, each with a carrier substrate which, after the respective ultra-broadband antenna is attached to another point of the measuring cell, replaces part of the surface of the measuring cell wall directed into the interior, or is located there in the interior and extends at a distance in front of the measuring cell wall. With radiator elements thus arranged at distributed locations of the measuring cell on or in the respective carrier substrate, a radar measurement with support points at different locations within the measuring cell can consequently be carried out, which essentially no longer sets any limits to the possible structural complexity of the fill level areas to be detected by sensors in the applicability of the object according to the invention . A simple example of ultra-broadband antennas attached to distributed locations in the measuring cell is the Fig. 3 can be seen in which in addition to the ultra-wideband antenna 202, similar to the Figs. 1 and 2 such a further ultra-wideband antenna 212 is used. It should be mentioned that a multiplicity of n such or similarly further ultra-broadband antennas 212 can also be used within the scope of the invention

In the following, individual preferred embodiments in connection with radiator elements arranged on or in the carrier substrate 205, which are connected to a coaxial conductor connection as a high-frequency connection 203, as mentioned above, which is also used for the wired transmission of an ultra-wideband signal between the radiator elements and the ultra-wideband microwave unit 201, will be discussed in particular is associated with this.

For example with Fig. 4 Outlined in plan view using a first embodiment of a dipole antenna, at least two planar radiator elements are expedient 206a, 206b arranged on or in the carrier substrate 205 of the ultra-broadband antenna 202. The planar radiator elements 206a, 206b extend essentially parallel to the carrier substrate 205, are held by the carrier substrate 205 in a common plane, ie in particular a common planar plane spanned by the planar radiator elements consequently extends essentially parallel to a plane spanned by the carrier substrate, and together form a surface dipole. Due to the design of the antenna as an electrically short antenna, a correspondingly designed surface dipole is consequently not adapted to the excitation frequencies. The emitter elements thus expediently also have a horizontal extent to the plane of the carrier substrate.

As also indicated at Fig. 4 , the high-frequency connection 203 is expediently also connected via an adapter 204 to the radiator elements 206a, 206b that form this surface dipole. This allows in particular impedance conversions between the line-bound asymmetrical transmission path of the ultra-broadband signals and the associated electromagnetic signal waves of the symmetrical surface dipole as well as the transmission path of the ultra-broadband signals that is based in the interior of the measuring cell, i.e. in particular based on the medium of air or generally speaking, non-line-bound transmission path of the ultra-broadband signals and the associated electromagnetic signal waves application-specific make as it is known in and of itself to a person skilled in the art. For example, the wave impedance of typical coaxial cables is 50Ω and the impedance of the surface dipole differs significantly depending on the frequency. A matching element 204, in a preferred embodiment, for example, a broadband balun transformer, is therefore generally useful to make appropriate adjustments to the wave impedance of the line at the transition between the line-bound electromagnetic signal waves and the surface dipole.

The ultra-wideband antenna 202 of FIG Fig. 4 can consequently be designed as a transmitting and receiving antenna, in particular monostatic. In this case, the ultra-wideband antenna 202 is the two, according to the present example Radiator elements 206a, 206b are thus expediently connected to a transmission module comprised by the ultra-broadband microwave unit for generating an ultra-broadband signal used for the measurement and, at the same time, with an evaluation module for evaluating a received ultra-broadband signal, which, however, is not shown in more detail for reasons of clarity.

Alternatively or in addition to this outlined Fig. 5 a cross-sectional view of an embodiment of a dipole antenna with radiator elements 206a, 206b embedded in the carrier substrate 205 for use within a system according to the invention.

As a modification of the Figs. 4 and 5 outlined Fig. 6 in plan view an embodiment of a dipole antenna, in particular for bi-static measurements for use within a system according to the invention. In addition to the two planar radiator elements 206a, 206b, namely horizontally parallel to these two planar radiator elements 206a, 206b, at least two further planar radiator elements, in the example shown, two further planar radiator elements 207a, 207b are included by the ultra-wideband antenna 202. In each case, two 207a, 207b of such at least two further planar radiator elements are held essentially parallel to the carrier substrate 205, extending from this in a common plane to each other and also together form a surface dipole , radiator elements forming a surface dipole, a high-frequency connection 203 designed in particular as a coaxial conductor connection for the wired transmission of an ultra-broadband signal between these radiator elements 207a, 207b and the ultra-wideband microwave unit (not shown) which is consequently also expediently connected to this high-frequency connection. Since, in the example shown, a separate high-frequency connection 203 is connected to the radiator elements 206a, 206b and to the radiator elements 207a, 207b, again in an expedient manner via a separate adapter 204, the ultra-wideband antenna 202 in this case can in particular also be set up for bi-static measurement, ie two of the one Radiator elements forming a surface dipole, e.g. the radiator elements 206a, 206b, are set up to transmit an ultra-broadband signal used for the measurement and are therefore expediently connected to at least one transmission module for generating the ultra-broadband signal used for the measurement and two other radiator elements forming a surface dipole, e.g. the radiator elements 207a, 2067 are set up to receive the ultra-wideband signal used for the measurement and are therefore expediently connected to at least one evaluation module for evaluating the received ultra-wideband signal. As can also be seen, the radiator elements each forming a common surface dipole can share a common carrier substrate, ie they are arranged on or in the same carrier substrate 205. As an alternative, however, the arrangement on a fundamentally divided carrier substrate would also come into consideration, ie the emitter elements forming a common surface dipole are each arranged on a partial carrier substrate.

Similar to the Fig. 5 outlined Fig. 7 a cross-sectional view of a further embodiment of a dipole antenna with emitter elements embedded in the carrier substrate 205 for use within a system according to the invention. In a further modification of the Fig. 5 and also to Fig. 6 are in accordance with the exemplary embodiment Fig. 7 however, in addition to the two planar radiator elements 206a, 206b, namely vertically parallel to these two planar radiator elements 206a, 206b, at least two further planar radiator elements, in the example shown, the two further planar radiator elements 207a, 207b comprised by the ultra-wideband antenna 202. These two further planar radiator elements are also held in this case, extending essentially parallel to the carrier substrate 205, in each case in a common plane to one another and each together basically form a surface dipole. Since in the example shown, all four shown two 207a, 207b of such at least two further planar radiator elements are shown embedded in the carrier substrate 205, it can be seen that such a carrier substrate 205 can also be designed, for example, as a multi-layer circuit board. This also has the advantage, for example, of being able to produce embedding elements in a simple manner, which is desired vertically parallel to one another. A multi-layer circuit board as a carrier substrate 205 can of course also be used without embedded radiator elements.

Furthermore, in one embodiment according to Fig. 7 According to a variant, it can be provided that a separate high-frequency connection 203 is connected to each of the radiator elements 206a, 206b and to the radiator elements 207a, 207b, again in an expedient manner via a separate adapter 204, which, however, is not shown for reasons of clarity . In an alternative variant, however, it can also be provided that the radiator elements 206a, 206b and the radiator elements 207a, 207b are connected to a common high-frequency connection 203. In this case, each radiator element 206a, 206b, which together form a surface dipole, is expediently electrically connected to a different one of the radiator elements 207a, 207b which together form a further surface dipole. According to Fig. 7 thus in particular the radiator element 206a with the radiator element 207a and the radiator element 206b with the radiator element 207b. However, this variant is also not shown for reasons of clarity.

The respective application-specific device of an ultra-wideband antenna 202, i.e. in particular for bi-static or monostatic measurements and as a transmitting and / or receiving antenna, is consequently extremely flexible within the scope and application of the invention. It should be pointed out that mixed forms of further planar radiator elements arranged horizontally and vertically parallel to the two planar radiator elements 206a, 206b are also within the scope of the invention. For example, two further planar radiator elements arranged horizontally and two vertically parallel to the two planar radiator elements 206a, 206b.

Fig. 8 Outlines a cross-sectional view of a further embodiment of an antenna according to the invention, in the example shown a dipole antenna with two radiator elements 206a, 206b embedded in the carrier substrate 205, with a rear shield 402, ie on the side facing away from the fill level area to be detected by sensors, also included. It has been shown to be useful if such or a similar shield 402 is not connected to the ultra-wideband microwave unit 201. Furthermore, it has been shown to be expedient in a complementary or alternative manner if the shielding 402 is formed by the metallic measuring cell wall itself or by a metallic cover of the ultra-broadband antenna 202. Rearward wave propagation of the ultra-wideband signal can thus be avoided in a simple manner, or at least reduced.

As can also be seen, the shielding 402, viewed from the carrier substrate, is thus arranged towards the first side and expediently at a distance from the carrier substrate 205. As shown, an inserted adapter 204 can expediently also be arranged between the shield 402 and the carrier substrate 205. In a practical embodiment, a cavity 210 is consequently also present between the shield 402 and the carrier substrate 205. Depending on the application, this can also be filled with a suitable gas (e.g. air) or vacuum, in particular to provide further, respectively desired dielectric properties to improve the radar measurement.

At the in Fig. 9 The embodiment of an antenna according to the invention sketched in a cross-sectional view, in the example shown of a dipole antenna with two radiator elements 206a, 206b embedded in the carrier substrate 205, is a modification of FIG Fig. 8 In particular, a protective layer 209 is arranged adjacent to the carrier substrate 205 and the first surface facing the first side, which is expediently formed by a non-conductive layer, in particular for covering, and / or by an absorber layer. Even with at least one such protective layer designed for covering and / or absorption, additional reflections on back layers, in particular also grounded layers, can thus be avoided in a simple manner. A broadband HF material in the form of a film or a foam has also proven to be particularly useful as such a protective layer 209, for example. As shown, an adapter 204 used within the scope of the invention can be embedded in the protective layer 209 and / or inserted within a cavity 210 formed in the protective layer 209. In the latter case, a existing free space in the cavern 210 between adapter 204 and protective layer 209, depending on the application, for example, can also be filled again with a suitable gas (for example air) or vacuum.

At the in Fig. 10 in cross-sectional view sketched embodiment is a hybrid of the in the Figs. 8 and 9 shown.

It is advantageous that the radiator elements 206a, 206b, 207a, 207b described above can in principle be of any shape. Depending on the requirement or application-specific, a large number of possible antenna structures can consequently be used for a particularly suitable design of a respective surface dipole built up by the radiator elements. Radiator elements have proven themselves within the scope of the invention, for example, for the formation of circular, elliptical and ring structures or also with butterfly structures, fly structures, i.e. "bow tie" structures, and so-called batwing structures. It has also proven to be particularly expedient if the ultra-broadband microwave unit is set up for a continuously periodic signal as an ultra-broadband signal, an ultra-broadband M-sequence signal having been shown to be particularly expedient.

In consideration of the above description, it can thus be summarized that the invention creates a sensor system suitable for industrial use for the presence detection of filling goods in small and / or complex-structured measuring cells, in particular containers, in particular for empty detection, for filling level measurement and for determining the volume of filling goods.

Due to the contactless volumetric detection of the filling level range and the presence of the filling material in geometrically complex volumes, e.g. also within metallic or non-metallic storage and process containers, in which the filling material can assume different physical states and shapes, dead areas can be avoided according to the invention and thus also measurements in the vicinity of the antenna be made possible. With an overall cost-effective structure, measurements down to the bottom of the container and into the corners of the container are possible.

Based on the system according to the invention, a large number of digital algorithms can then be used for the subsequent signal evaluation and data analysis relating to the presence detection and calculation of the physical properties of the filling material, e.g. using a time-based impedance jump detection, including using KI (artificial Intelligence) including machine learning, a sub-area of artificial intelligence in which the recognition of patterns in existing data sets enables a system to carry out independent analyzes and problem solutions., For presence detection, calculation of the physical properties of the product

The ultra-broadband antennas set up within the scope of the invention have a high dispersive / non-directional radiation characteristic or have such field propagation properties. The electromagnetic field generated using the ultra-broadband signals is propagated in a spherical, at least hemispherical and thus volumetric manner into the measuring cell, in particular container, i.e. similar to a capacitive proximity sensor, not directly in the direction of the product. Multiple reflections on metallic walls and fixtures can also occur here, which of course must also be taken into account accordingly.

The dipole structures proposed according to the invention instead of patch antennas can be made much more complex and, using a multilayer printed circuit board, can also extend in the direction of the measuring cell area, ie the filling level area to be detected by sensors. They can also be completely embedded in the carrier substrate, for example in a multi-layer circuit board, which in particular can also be done using a vertical integration technique; an inserted adapter can also be embedded here.

List of reference symbols

100

Level radar with bundling antennas

101

Microwave electronics

102

Bundling antenna

103

Ground plane or reflector layer

104

High frequency connection

200

Measurement system according to the invention

201

Ultra wideband microwave unit

202

Ultra broadband antenna

203

High frequency connection

204

Adapter

205

Carrier substrate

206

Radiator element of the surface dipole

207

Radiator element of a further surface dipole

209

Protective layer

210

cavern

212

nth ultra-wideband antenna

300

container

301

Container wall

400

Measuring cell, especially in the form of an arbitrarily structured container

401

Measuring cell wall, in particular formed by the container wall

402

shielding

403

Shielded area

500

Filling material

501

Product surface

502

dielectric body or fabric

503

nth dielectric body or substance

504

Surface of a body or substance

600

Bundled measuring field

601

Directional lobe

602

Transmission signal

603

Received signal

700

Voluminous measuring field

702

Transmission signal

703

Received signal

704

reflected transmission signal

705

reflected received signal

Claims (15)

System for the detection and / or volume determination of bodies or substances made of dielectric and / or conductive material (500, 502, 503, 504) within an interior of a measuring cell (400), in particular in the form of a container, with a conductive and / or non-conductive measuring cell wall (401) having an interior-facing surface comprising: - an ultra-wideband microwave unit (201), and - At least one ultra-broadband antenna (202) with at least one disk-shaped carrier substrate (205) with a first surface directed towards a first side and a second surface directed opposite to the first surface, which forms an outer side of the antenna, the carrier substrate being arranged and provided to replace part of the surface of the measuring cell wall directed into the interior space or to extend in the interior space at a distance in front of the measuring cell wall during operation, in particular after fastening the ultra-broadband antenna to the measuring cell characterized in that
the ultra-wideband antenna with radiator elements arranged on or in the carrier substrate is set up as an electrically short antenna with an at least substantially hemispherical radiation characteristic, for covering a voluminous measurement field (700). The system of claim 1, wherein - two planar radiator elements (206a, 206b) are arranged on or in the carrier substrate, which are held in a common plane and extend essentially parallel to the carrier substrate and together form a surface dipole, and - A high-frequency connection (203) connected to the radiator elements (206a, 206b), to which the ultra-broadband microwave unit (201) is also connected, for the wired transmission of an ultra-broadband signal between the radiator elements and the Ultra wideband microwave unit (201), System according to claim 2, wherein horizontally and / or vertically parallel to the two planar radiator elements (206a, 206b) at least two further planar radiator elements (207a, 207b) are included, two of these at least two further planar radiator elements being essentially parallel to the carrier substrate extending from this are held in each case in a common plane to one another and together form a surface dipole. System according to claim 3, wherein a high-frequency connection (203) for wired transmission of an ultra-broadband signal between these radiating elements and the ultra-wideband microwave unit (201) which is also connected to this high-frequency connection is connected to the two further emitter elements forming a surface dipole. System according to one of the preceding claims, wherein each high-frequency connection is connected via a matching element (204), in particular for impedance conversion, to the radiator elements each forming a surface dipole. System according to one of the preceding claims, wherein the ultra-wideband antenna (202) comprises a shielding (402) arranged at a distance from the carrier substrate towards the first side and from the carrier substrate (205). System according to the preceding claim, wherein the shield (402) is not connected to the ultra-broadband microwave unit (201) and / or wherein the shield (402) is formed by the metallic measuring cell wall or a cover of the ultra-broadband antenna (202). System at least according to the preceding claims 5 and 6, wherein the adapter (204) is between the shield and the carrier substrate is arranged. System according to one of the preceding claims, wherein a non-conductive and / or absorber layer is arranged as a protective layer (209) adjacent to the carrier substrate towards the first side. System at least according to the preceding claims 5 and 9, wherein the adapter (204) is embedded in the protective layer (209). System according to one of the preceding claims, wherein the ultra-wideband microwave unit is set up for the use of a continuously periodic signal as the ultra-wideband signal. The system of any preceding claim, wherein the ultra-wideband microwave unit comprises a transmitter module for generating an ultra-wideband signal. System according to one of the preceding claims, wherein the ultra-broadband microwave unit comprises an evaluation module for evaluating a received ultra-broadband signal. System according to one of the preceding claims, wherein at least one further ultra-wideband antenna (212) is set up with the features according to one of the preceding claims 1 to 6, wherein the ultra-wideband antenna (212) is connected to at least one evaluation module for evaluating a received ultra-wideband signal System according to one of the preceding claims, wherein the carrier substrate is a multi-layer circuit board, and / or the radiator elements are embedded in the carrier substrate.

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